Child Height Predictor

Adult height is largely inherited, so a child's likely range can be estimated from the parents. This calculator applies the mid-parental height method, which gives a central estimate and a range — useful for reassurance, and not a substitute for growth-chart tracking by a clinician.

Inputs

Result

177 cm

Typical range 169–185 cm

How the child height predictor works

Mid-parental height: average the parents' heights, then add 6.5 cm for a boy or subtract 6.5 cm for a girl.

The prediction carries a range of roughly ±8.5 cm, which covers about 95% of outcomes — genetics sets a corridor, not a point.

Nutrition, sleep, chronic illness and hormonal conditions all influence whether a child reaches the genetic potential the formula describes.

Worked example: father 178 cm, mother 165 cm

  1. Mid-parental height: (178 + 165) ÷ 2 = 171.5 cm.
  2. For a son: 171.5 + 6.5 = 178 cm.
  3. For a daughter: 171.5 − 6.5 = 165 cm.
  4. Likely range for the son: about 169.5 to 186.5 cm.
  5. Likely range for the daughter: about 156.5 to 173.5 cm.

Common mistakes to avoid

Reading the central estimate as a prediction

The ±8.5 cm range is the honest answer. A single number implies precision the method does not have.

Comparing height to peers rather than a chart

Growth velocity on a percentile chart matters far more than absolute height. A child tracking steadily along the 15th percentile is usually fine.

Expecting steady growth

Growth comes in spurts, and puberty timing shifts everything. Early developers look tall then plateau; late developers catch up.

Frequently asked questions

How accurate is the mid-parental method?

It predicts within about 8.5 cm for 95% of children. Bone-age radiographs give a tighter estimate when clinically needed.

At what age does growth stop?

Typically 14–16 for girls and 16–18 for boys, when the growth plates close. Small gains can continue into the early twenties.

Can nutrition change final height?

Poor nutrition or chronic illness can prevent a child reaching genetic potential. Beyond adequacy, extra food and supplements do not add height.

Does sleep affect growth?

Growth hormone is released mostly during deep sleep, so chronic sleep restriction in children is a genuine concern.

When should I see a doctor about growth?

If a child crosses two percentile lines downward, grows less than about 4 cm a year in mid-childhood, or is far outside the predicted range.

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